Simple Index to Predict Likelihood of Skilled Nursing Facility Admission After Coronary Artery Bypass Grafting Among Older Patients

Background: Acceptable short-term mortality rates for elderly patients undergoing coronary artery bypass grafting (CABG) are reported in the literature. However, rather than death, older patients considering CABG are generally most concerned about a postoperative loss of functional independence. To address this concern, we describe an index that predicts a patient's likelihood of admission to a skilled nursing facility (SNF) after CABG. Methods: Logistic regression analysis of the California hospital discharge database during a 5-year period was performed to identify the most prevalent preoperative International Classification of Disease, 9th Revision Clinical Modification (ICD-9-CM) diagnoses associated with SNF admission after primary CABG in patients aged 65 years or older. Each diagnosis was weighted according to odds ratios to develop an index that predicts the likelihood of discharge to a SNF. The index was validated using our institutional database. Results: A total of 26,040 patients (mean age, 74.2 years; 67.2% men) fit our criteria. They had an in-hospital mortality rate of 3.09% and a 17.3% SNF discharge rate. Our index was a summation of nine selected preoperative ICD-9-CM diagnoses, which were assigned a value of 1 point (osteoarthritis, congestive heart failure, atrial fibrillation, myocardial infarction, anemia, obesity) or 2 points (female, chronic obstructive pulmonary disease, renal failure). Validation analysis produced a C statistic and pseudo r² value of 0.6435 and 0.0408, respectively. Cut-point analysis suggests that patients with scores of 3 or higher can be considered "high-risk.". Conclusions: We describe a simple index to identify older patients at low-risk and high-risk for SNF admission after CABG. Such tools may be useful in counseling older patients considering CABG.